RT5C348B中文资料2线串行接口数据手册Nisshinbo规格书

描述 Description

The Rx5C348 are CMOS real-time clock ICs connected to the CPU by four signal lines, CE, SCLK, SI, SO, and configured to perform serial transmission of time and calendar data to the CPU. The periodic interrupt circuit is configured to generate interrupt signals with six selectable interrupts ranging from 0.5 seconds to 1 month. The 2 alarm interrupt circuits generate interrupt signals at preset times. As the oscillation circuit is driven under constant voltage, fluctuation of the oscillator frequency due to supply voltage is small, and the time keeping current is small (TYP. 0.35 µA at 3V: Rx5C348A, TYP. 0.55 µA at 3V: Rx5C348B). The oscillation halt sensing circuit can be used to judge the validity of internal data in such events as power-on; The supply voltage monitoring circuit is configured to record a drop in supply voltage below two selectable supply voltage monitoring threshold settings. The 32.768 kHz clock output function (N-channel open drain output) is intended to output sub-clock pulses for the external microcomputer. The 32-kHz clock circuit can be disabled by certain register settings for the Rx5C348A but cannot be disabled by any register settings for the Rx5C348B. The oscillation adjustment circuit is intended to adjust time counts with high precision by correcting deviations in the oscillation frequency of the crystal oscillator. SSOP10 and SSOP10G packages are available.

特性 Features

• Timekeeping supply voltage：1.45 to 5.5 V；
• Supply Current：Rx5C348A: Typ. 0.35 µA (VDD=3V),Rx5C348B: Typ. 0.55 µA (VDD=3V)；
• Connected to the CPU：Four signal lines (CE, SCLK, SI, and SO), Maximum clock frequency of 2 MHz (with VDD = 5V)；
• Functions：Time counters (counting hours, minutes, and seconds) and calendar counters (counting years, months, days,and weeks) (in BCD format)；
• Interrupt circuit configured to generate interrupt signals (with interrupts ranging from 0.5 seconds to 1 month) to the CPU and provided with an interrupt flag and an interrupt halt；
• 2 alarm interrupt circuits (Alarm_W for week, hour, and minute alarm settings and Alarm_D for hour and　minute alarm settings)；
• Oscillation halt sensing circuit which can be used to judge the validity of internal data；
• Supply voltage monitoring circuit with two supply voltage monitoring threshold settings；
• Automatic identification of leap years up to the year 2099；
• Selectable 12-hour and 24-hour mode settings；
• Clock Output：32-kHz (Nch. open drain output),The Rx5C348A is designed to disable 32-kHz clock output in response to a command from the host computer and the Rx5C348B is designed to keep 32-kHz output enabled.；
• Built-in Circuits：Oscillation stabilization capacitors (CG and CD)；
• High precision oscillation adjustment；
• Packages：SSOP10G, SSOP10；

应用 Application

• Home appliances such as refrigerators, rice cookers, and electric pots
• Digital appliances such as laptops, digital TVs, DSCs, camcorders, mobile phones, and private LAN system
• Office appliances such as copiers, printers, facsimiles, scanners, and projectors